With her pooch in tow, the Gossip Girl star celebrates her 21st b-day on the New York City set of her show. Plus: Ashlee Simpson, Lindsay Lohan, Paris Hilton and more


Who says you can't go home again? Shannen Doherty, who will debut her scandalous return to Beverly Hills Sept. 2, makes a stunning arrival Saturday at the L.A. premiere party for 90210 in Malibu.